The present invention relates to a vertical plane counterbalancing structure, particularly for support heads for television or motion picture cameras.
As is well known, in fluid heads for camera supports, balancing the camera weight is necessary both on the horizontal plane and the vertical plane.
No difficulty exists in obtaining balance on the horizontal plane, since the weight of the camera is supported by a high efficiency system, generally comprised of a ball thrust bearing having a suitable diameter.
However, the problem relevant to balancing on the vertical plane is different, since the angular displacement of the camera causes a turning over moment, or an "acting agent", which varies based on the angular displacement.
In order to obtain the same conditions as in the horizontal plane, the acting moment must be annulled by an opposite or "reagent" moment, having the same and opposite value all along the -90.degree./+90.degree. motion arc.
In other words, the barycenter of the system (camera plus head) varies in any angular situation, so that it is practically impossible to obtain a perfect and constant balancing throughout the arc of motion.
The importance of an optimum balancing in any position along the 180.degree. arc (-90.degree./+90.degree.) is very high since it remarkably influences the quality of the film or video being shot.
At present, known counterbalance solutions do not provide a complete solution to the above problem along the whole arc of motion.